In a mixer, cream together the butter and the sugar until light and fluffy.,Scrape down the sides of the bowl with a rubber spatula, then beat the egg.,Cream until the mixture is light and lemon-colored.,Add the molasses and mix until combined.,Scrape down the side of the bowl.,In a separate bowl, stir together the salt, ginger, cinnamon, and baking soda.,Add this to the butter mixture and mix until combined.,______,Wrap in plastic and chill at least 2 hours or overnight.,Preheat the oven to 350 degrees F and lightly grease two baking sheets.,Roll the dough into balls 1/2 to 2 inches in diameter (depending on what size you like them) and arrange them in well-spaced rows on the cookie sheets.,Bake about 10-12 minutes, just until crisp.,The cookies will be thin and flat.,Let cool on the baking sheet 2 minutes, then transfer to wire racks.,When cool, store in an airtight container.